The present invention relates in general to inflatable occupant restraint systems for transportation vehicles, and, more specifically, to airbag deployment during a side impact.
Supplemental restraint systems in passenger cars and trucks include frontal airbags, side curtain airbags, thorax airbags, pelvis airbags, and inflatable knee bolsters, for example. Deployment strategies for inflating the restraints attempt to optimize airbag deployment in a way that gives maximum protection to occupants in response to a type of impact, its direction and severity, and an approximate location and size of the occupants. In some instances of a frontal crash, a combination of airbags may be deployed such as a frontal airbag and a knee bolster. In some instances of a side impact with sufficient severity, pelvis and thorax bags and a side curtain airbag may be deployed without deploying the frontal airbag. Many other combinations are also used.
Adaptive airbag systems typically adjust the inflation force and/or the inflated shape of an airbag to tailor its deployment to a particular occupant or crash situation. Information concerning the severity of a crash and the occupant's location, weight, and/or relative size may be used by a control unit or algorithm to selectably deploy portions of multi-stage airbags or to control active vents according to a desired deployment pressure or force, for example.
The packaging space for installing airbag devices within a vehicle interior is limited. Thus, it would be desirable to employ a restraint system architecture and an associated deployment strategy that provides optimal protection and utilizes existing safety-related components in an efficient manner. A typical vehicle includes several inflatable restraints designed to protect each of the driver and a front seat occupant. When a front occupant seat is empty, passenger airbags are typically not deployed in order to minimize the need for subsequent replacement of the passenger airbag device.
In recent years, the relative frequency of side impacts with respect to frontal impacts has been increasing. Typically, pelvis and thorax bags and a side curtain airbag may deploy on the struck side of a vehicle during a side impact in order to protect a passenger on that side of the vehicle. When the struck side corresponds to the passenger side of the vehicle and the corresponding passenger seat is empty, then pelvis and thorax bags and the side curtain airbag on the struck passenger side are not deployed.
A far side impact is an event wherein a vehicle is struck on a side remote from the vehicle occupant under consideration. In other words, with regard to the driver, a far side impact occurs on the passenger side of the vehicle. In such an impact, the driver may be accelerated toward the passenger side of the vehicle. This would be true even for a driver wearing a seat belt because the shoulder belt is not designed for side impacts, so the upper torso of the driver can move out of the shoulder belt in response to the lateral acceleration of a far side impact. The movement can potentially cause a lateral shear and other distortions of the driver's body and/or an impact with structures on the passenger side of the vehicle (especially in smaller cars).
In order to provide enhanced far side impact protection, additional inflatable restraints have been used which deploy from a central console, roof, windshield header, or the inboard side of the front seats. It would be desirable to provide enhanced far side impact protection for a driver without incurring the increased complexity and potential out-of-position risks associated with such additional airbags.